Hydraulic extrusion press



May 7, 1968 w. I INNr-:Rz 3,381,512

HYDRAULIC EXTRUSION PRESS Filed Ju-ly 21, 1965 2 Sheets-Sheet 1 I nvenor: WILHELM NERZ ATTORNEY.

May 7, 1968 w. I lNNERz HYDRAULIC EXTRUSION PRESS 2 Sheets-Sheet 2 Filed July 2l, 1965 Invenar: WILHELM LINNERZ 6l 45 ATTORNE United States Patent O 4 claims. (ci. 72-265) ABSTRACT F THE DISCLOSURE A hydraulic extrusion press in which the substantially frame-shaped head of the main ram and the cross piece or carriage reciprocable therein to actuate the mandrel rod are each supported independently of each other by its own prop means such as glide shoes which move either upon separate or upon common guide means integral with the press frame.

My invention relates to hydraulically operated presses particularly adaptable for the extrusion of metal into shapes such as tubes or bars and more specifically to such extrusion presses which combine in one unit a tubular or similarly hollow extrusion stem and a mandrel rod or piercing plunger. In presently known presses of this type the tubular press ram is attached to and actuated by the head of a power operated main ram which is reciprocable in a stationary base frame and which houses and guides a separately power operated cross piece, or slide or carriage from which the said mandrel rod or piercing plunger longitudinally extends centrally into the hollow of the tubular extrusion stem. Such presses are nowadays generally preferred because of their compactness and reduced overall length.

When presses of said type are used to extrude precise hollow bodies, such as tubes, it is important that the piercing plunger remains at all times accurately centered in the tubular extrusion stem. This, however, is not reliably achieved in the known presses of this type because the said cross-piece or carriage housed in and guided by the head portion of the main ram is exposed to great pressures, and therefore also the mandrel rod or piercing plunger held by and extending from the cross piece or carriage, are often radially and/or angularly dislocated relative to the extrusion stem by unavoidable and uncontrollable deformations arising in the head portion of the main ram. Though such dislocations of the ram head and of the cross piece or carriage are small, they appear in increased measure in the operating end of the punching tool and result in unprecise extrusion prodnets.

It is an object of my invention to avoid the beforesaid disadvantage. To this effect said cross piece, slide or carriage reciprocable within and relative to the ram head is corporally separated and independent from the ram head and is separately supported by its own prop means which are and guided by track means on the stationary base frame of the press. These track means for the cross piece or carriage, for example guide rails, may either be the same as the track means for the ram head or they may be distinct for each. Additionally the cross piece or carriage may be connected with radial play to the piston rod of its power driving means arranged in the main ram so that deformations of the ram head will be compensated by said play and will not influence the cross piece or carriage and the piercing tool.

The said and other objects of my invention will be more fully understood from the following specication ice when read with the accompanying drawing which illustrates diagrammatically one preferred embodiment; however structural elements not important for the understanding of my invention such as the billet or box container, the matrix unit and its supports, the tubings for the pressure medium of the hydraulic drive means and other conventional elements, are not shown.

In the drawing FIG. 1 shows a vertical longitudinal section of my new extrusion press on line 1-1 of FIG. 2, and

FIG. 2 shows a cross section on line 2-2 of FIG. 1.

My new press includes like known presses a main ram 15 having a frameshaped or chambered ram head 11 which is provided with glide shoes 12 sliding upon guide rails 13 mounted on the stationary base frame 14. The main ram 15 is operated in the stationary hydraulic cylinder 16. An exchangeable tubular extrusion stem 17 extends from the forward end of the ram. head 11 in axial direction thereof. The cylinder 16 of the main ram 15 is firmly connected to the not shown conventional'rnatrix unit by the rods 18 illustrated in FIG. l only partly and in FIG. 2 in cross section.

The head portion 11 of the main rain 15 houses reciprocably therein a cross piece or carriage 19. Rigidly attached to the forward end of this cross piece is a mandrel rod or plunger 20 by means of its collar 21 and the bush 22. The rod 20 bears at its forward end a piercing tool 23 and both extend with considerable clearance centrally into the hollow of the tubular extrusion stem 17. The cross piece 19 is reciprocated within the ram head 11 by piston rod 24 and piston 25 which operates in a cylindrical axial boring within the main ram 15.

Whereas in hitherto known presses of the type described the cross piece 19 is supported and guided by the frameshaped ram head 11, so that the disadvantages stated above arise, according to my invention the cross piece 19 and the ram head 11 are independent from each other. For this purpose l provide the cross piece 19 with its own prop members such as glide shoes 26 which freely extend beyond the ram head 11 and move on track means upon the base frame. These track means may be as shown the same as the track means 13 for the prop means 12 of the ram head 11, or` they may be separate.

To increase and fully insure the independence of the cross piece 19 from the ram head 11 and to avoid any mutual influence, the piston rod 24 guided in the main ram 15 and actuating the cross pieces 19 is preferably attached thereto with radial clearance as shown at 27.

While one specific embodiment of my invention has been described and diagrammatically shown to illustrate the application of the principles of my invention, it will be understood that the same may be otherwise embodied without departing from such principles.

What I claimed as my invention is:

1. In a hydraulic extrusion press the improvement comprsing in combination a stationary base frame; a main ram having a substantially frameshaped head portion; first hydraulic drive means actuating said main ram relative to the base frame; lirst prop means associated with the said head portion to displaceably support the same on the base frame; first guide means on the base frame for said rst prop means; a cross piece connected to and actuating a mandrel rod, said cross piece reciprocably housed in said head portion for displacement in longitudinal direction hereof; second hydraulic drive means associated with the main ram to effect said displacement of the crosspiece; second prop means associated with the crosspiece to movably support the same on the base frame independently of the first prop means; and second guide means on the base frame for said second prop means.

2. In a hydraulic extrusion press the improvement according to claim 1 wherein at least one of said rst and second prop means are glide shoes.

3. In a hydraulic extrusion press the improvement according to claim 1 comprising unied first and second guide means.

4. In a hydraulic extrusion press the improvement according to claim 1 wherein said second hydraulic drive means comprise a piston with piston rod reciprocable the cross-piece with radial play.

References Cited UNITED STATES PATENTS 1,049,641 1/1913 Astfalck 72264 1,859,990 5/1932 Schlenstedt 72--264 2,903,130 9/1959 Reichl 72-260 RICHARD I. HERBST, Primary Examiner.

K. C. DECKER, Assistant Examiner. 

